best way to convert PDFs to EPUB ?

diskette · 03-03-2016, 09:15 AM

just wondered what kinds of results you guys have gotten from different conversion methods, and which you think is the best ?

i tried the top google hit: http://ebook.online-convert.com/convert-to-epub
and found it to be quite lacking

so next i'm trying calibre

any other ideas ?

dwig · 03-03-2016, 09:35 AM

#1 You should search the forum first. You'll find a wealth of info on this topic.
#2 If you must repeat a much asked question, you should post in the correct forum: https://www.mobileread.com/forums/forumdisplay.php?f=184 (maybe a forum moderator will move this one for you).
#3 You should read the Stickies there.
#4 Most importantly, there is absolutely no "best" way to convert PDFs to anything else, period. One, because there is a wide range of possible entities in PDFs and each convert with differing issues so each PDF is its own separate challenge. And two, because there are no "good" methods, much less "excellent" ones, you should search for "the least bad".

eschwartz · 03-03-2016, 09:48 AM

#5) ebook.online-convert.com uses calibre under the hood. An old version of calibre.

And I cannot overstress the importance of point #4 -- PDF is a truly horrible source format, prepare for a lot of elbow grease.

Cinisajoy · 03-03-2016, 10:26 AM

Find a good formatter and pay them major bucks.
There is no good way.
Well there is another way. Retype the entire thing in a doc format then convert.

Converting can be done but the results are usually not good.

Note: you can put PDFs on an ereader but it usually isn't pretty.

HarryT · 03-03-2016, 10:49 AM

A decent OCR program such as Abbyy FineReader is widely considered to be the best way to do it.

Cinisajoy · 03-03-2016, 11:50 AM

Harry where can I find this program?

Ken Maltby · 03-03-2016, 11:52 AM

As mentioned PDF is a document format not so good as an e-book format. If you just want to read the PDF, on your Kobo Touch, you could try KOReader. See the KOReader subforum under the E-Book Software Forum. An install guide.

Luck;
Ken

AnemicOak · 03-03-2016, 12:02 PM

Quote:

Originally Posted by Cinisajoy

Harry where can I find this program?

http://www.abbyy.com/finereader/

frostschutz · 03-03-2016, 05:52 PM

There is no "best" method as it depends a lot on the PDF in question. There are PDF that can be converted perfectly if they originated from a text processor and the original source was perfectly formatted and the PDF did not use any obfuscations or visual elements. There are PDF that can not be converted at all so you have to resort to pure imagery based OCR. It all depends on the situation.

My favourite way of converting PDF is to use poppler's pdftohtml -xml which for each line of text gives the coordinates and font properties in the XML metadata; and then write a small script specific to that PDF which turns it into a properly structured document. But doing it this way requires some scripting / regular expression knowledge.

diskette · 03-04-2016, 06:31 AM

Quote:

Originally Posted by dwig

#2 If you must repeat a much asked question https://www.mobileread.com/forums/forumdisplay.php?f=184

well i was looking for something more kobo specific, but yes i hadn't thought to search it first, and will check out the link. i also hoped that by posting in a subforum for developers i could yield more complex but better results

Quote:

Originally Posted by dwig

there is a wide range of possible entities in .PDFs and each convert with differing issues so each .PDF is its own separate challenge.

ah, wasn't aware of this, i figured it was only the target e-reader of the conversion that differed much

Quote:

Originally Posted by eschwartz

#5) ebook.online-convert.com uses calibre under the hood. An old version

ah i did suspect that this could be the case, just before trying calibre !

Quote:

Originally Posted by frostschutz

converting PDF is to use poppler's pdftohtml -xml which for each line of text gives the coordinates and font properties in the XML metadata; and then write a small script specific to that PDF which turns it into a properly structured document.

i may have to look into this, it seems .PDF formats are much more widely available than .EPUBs

i recall, when using a friend' kindle for a month, that amazon have their own PDF conversion tool, that you can use when sending to kindle via e-mail. i was thinking you could setup a jailbroken kindle, and then convert them to .EPUB, if .AZW to .EPUB is an easier conversion ? and then you could even set up a website that allows others to use this method.
but honestly i didn't even test out the conversion from .PDF enough on the kindle, and have never tested .AZW to .EPUB, to vouch whether it's worthwhile, but it'd be nice to have amazon do the work instead

though maybe that would also be calibre underneath !

eschwartz · 03-04-2016, 10:04 AM

Quote:

Originally Posted by diskette

well i was looking for something more kobo specific, but yes i hadn't thought to search it first, and will check out the link. i also hoped that by posting in a subforum for developers i could yield more complex but better results

There is nothing Kobo-specific to find.

There are three types of people:

People who know nothing about Kobos, and a lot about PDF.
People who know a lot about Kobos, and a lot about PDF.
People who know a lot about Kobos, and nothing about PDF.

4. Irrelevant people who know nothing about either one.

You want to attract the attention of #1 & #2.
Instead you posted where you could attract #2 & #3.
The existence of #2 is a matter of sheer coincidence, and that coincidence is the only reason you got any answers at all.*

"hoped that by posting in a subforum for developers i could yield more complex but better results" -- that is what I call spam.

This subforum is devoted to hacking the hardware and software of Kobo devices, there is no overlap with PDF processing at all.
The internet is filled with technical forums for very complex and obscure fields, most of which have nothing to do with PDF, and most of which aren't interested in PDF questions cluttering up the place.

tl;dr
The proper place to ask questions about PDF is in the calibre conversion subforum, or the PDF subforum.
This is for your sake, so you are more likely to get answers.

Quote:

i recall, when using a friend' kindle for a month, that amazon have their own PDF conversion tool, that you can use when sending to kindle via e-mail. i was thinking you could setup a jailbroken kindle, and then convert them to .EPUB, if .AZW to .EPUB is an easier conversion ? and then you could even set up a website that allows others to use this method.
but honestly i didn't even test out the conversion from .PDF enough on the kindle, and have never tested .AZW to .EPUB, to vouch whether it's worthwhile, but it'd be nice to have amazon do the work instead

though maybe that would also be calibre underneath !

And now you are asking in the Kobo subforum about using Amazon's Send-to-Kindle service.

* -- Well, I know nothing about Kobos but I still saw this thread simply because I don't have the subforum ignored.

Cinisajoy · 03-04-2016, 10:15 AM

Hey eschwartz,
One good thing did come out of this thread. I found a good ocr.

diskette · 03-04-2016, 10:44 AM

yes i was fishing for infomation on amazon's send-to-kindle service, as i don't have one, but maybe someone has an idea of how to use it without having a kindle ---- ahhhh i just remembered. i think it may be accessible from their servers on their 'manage my content and devices' after you send the conversion e-mail. so perhaps i can use a friend's amazon account and then toy with .AZW conversion

feel free to send a quick message to a mod to move it, if it frustrates you so !

Cinisajoy · 03-04-2016, 11:22 AM

Quote:

Originally Posted by diskette

yes i was fishing for infomation on amazon's send-to-kindle service, as i don't have one, but maybe someone has an idea of how to use it without having a kindle ---- ahhhh i just remembered. i think it may be accessible from their servers on their 'manage my content and devices' after you send the conversion e-mail. so perhaps i can use a friend's amazon account and then toy with .AZW conversion

feel free to send a quick message to a mod to move it, if it frustrates you so !

Hi.
2 quick things.
1. If they are scanned PDFs, copy and paste won't work.
2. One has to own a kindle to use the send to kindle feature.
Every kindle is assigned its own email address.

Rizla · 03-04-2016, 11:35 AM

1) The best converter I've found is Abbyy FineReader (for both OCR and text-based PDFs).

Unfortunately PDF conversion often leaves a lot of unwanted carriage returns / newlines and incomplete lines dangling. Does anyone know of a program to fix this? It's a drag doing it manually via regex in an editor. Calibre sort of does it, with mixed results (maybe I just haven't mastered it.)

2) Another option is to reformat the PDF for a 6" screen using k2pdfopt:
http://www.willus.com/k2pdfopt/
It's a pretty amazing program.

3) Honorable mention goes to Koreader, though I find it doesn't work with all PDFs.

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03-03-2016, 09:15 AM	#1
diskette Member Posts: 11 Karma: 450 Join Date: Jan 2016 Device: kobo touch	best way to convert PDFs to EPUB ? just wondered what kinds of results you guys have gotten from different conversion methods, and which you think is the best ? i tried the top google hit: http://ebook.online-convert.com/convert-to-epub and found it to be quite lacking so next i'm trying calibre any other ideas ?

03-03-2016, 09:35 AM	#2
dwig Wizard Posts: 1,613 Karma: 6718541 Join Date: Dec 2004 Location: Paradise (Key West, FL) Device: Current:Surface Go & Kindle 3 - Retired: DellV8p, Clie UX50, ...	#1 You should search the forum first. You'll find a wealth of info on this topic. #2 If you must repeat a much asked question, you should post in the correct forum: https://www.mobileread.com/forums/forumdisplay.php?f=184 (maybe a forum moderator will move this one for you). #3 You should read the Stickies there. #4 Most importantly, there is absolutely no "best" way to convert PDFs to anything else, period. One, because there is a wide range of possible entities in PDFs and each convert with differing issues so each PDF is its own separate challenge. And two, because there are no "good" methods, much less "excellent" ones, you should search for "the least bad". Last edited by dwig; 03-03-2016 at 12:07 PM.

03-03-2016, 09:48 AM	#3
eschwartz Ex-Helpdesk Junkie Posts: 19,421 Karma: 85400180 Join Date: Nov 2012 Location: The Beaten Path, USA, Roundworld, This Side of Infinity Device: Kindle Touch fw5.3.7 (Wifi only)	#5) ebook.online-convert.com uses calibre under the hood. An old version of calibre. And I cannot overstress the importance of point #4 -- PDF is a truly horrible source format, prepare for a lot of elbow grease.

03-03-2016, 10:26 AM	#4
Cinisajoy Just a Yellow Smiley. Posts: 19,161 Karma: 83862859 Join Date: Jul 2015 Location: Texas Device: K4, K5, fire, kobo, galaxy	Find a good formatter and pay them major bucks. There is no good way. Well there is another way. Retype the entire thing in a doc format then convert. Converting can be done but the results are usually not good. Note: you can put PDFs on an ereader but it usually isn't pretty.

03-03-2016, 10:49 AM	#5
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383099 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	A decent OCR program such as Abbyy FineReader is widely considered to be the best way to do it.

03-03-2016, 11:50 AM	#6
Cinisajoy Just a Yellow Smiley. Posts: 19,161 Karma: 83862859 Join Date: Jul 2015 Location: Texas Device: K4, K5, fire, kobo, galaxy	Harry where can I find this program?

03-03-2016, 11:52 AM	#7
Ken Maltby Wizard Posts: 4,466 Karma: 6900052 Join Date: Dec 2009 Location: The Heart of Texas Device: Boox Note2, AuraHD, PDA,	As mentioned PDF is a document format not so good as an e-book format. If you just want to read the PDF, on your Kobo Touch, you could try KOReader. See the KOReader subforum under the E-Book Software Forum. An install guide. Luck; Ken

03-03-2016, 05:52 PM	#9
frostschutz Linux User Posts: 2,282 Karma: 6123806 Join Date: Sep 2010 Location: Heidelberg, Germany Device: none	There is no "best" method as it depends a lot on the PDF in question. There are PDF that can be converted perfectly if they originated from a text processor and the original source was perfectly formatted and the PDF did not use any obfuscations or visual elements. There are PDF that can not be converted at all so you have to resort to pure imagery based OCR. It all depends on the situation. My favourite way of converting PDF is to use poppler's pdftohtml -xml which for each line of text gives the coordinates and font properties in the XML metadata; and then write a small script specific to that PDF which turns it into a properly structured document. But doing it this way requires some scripting / regular expression knowledge.

03-04-2016, 10:15 AM	#12
Cinisajoy Just a Yellow Smiley. Posts: 19,161 Karma: 83862859 Join Date: Jul 2015 Location: Texas Device: K4, K5, fire, kobo, galaxy	Hey eschwartz, One good thing did come out of this thread. I found a good ocr.

03-04-2016, 10:44 AM	#13
diskette Member Posts: 11 Karma: 450 Join Date: Jan 2016 Device: kobo touch	yes i was fishing for infomation on amazon's send-to-kindle service, as i don't have one, but maybe someone has an idea of how to use it without having a kindle ---- ahhhh i just remembered. i think it may be accessible from their servers on their 'manage my content and devices' after you send the conversion e-mail. so perhaps i can use a friend's amazon account and then toy with .AZW conversion feel free to send a quick message to a mod to move it, if it frustrates you so !

03-04-2016, 11:35 AM	#15
Rizla Member Retired Posts: 3,183 Karma: 11721895 Join Date: Nov 2010 Device: Nook STR (rooted) & Sony T2	1) The best converter I've found is Abbyy FineReader (for both OCR and text-based PDFs). Unfortunately PDF conversion often leaves a lot of unwanted carriage returns / newlines and incomplete lines dangling. Does anyone know of a program to fix this? It's a drag doing it manually via regex in an editor. Calibre sort of does it, with mixed results (maybe I just haven't mastered it.) 2) Another option is to reformat the PDF for a 6" screen using k2pdfopt: http://www.willus.com/k2pdfopt/ It's a pretty amazing program. 3) Honorable mention goes to Koreader, though I find it doesn't work with all PDFs.